A group of international researchers from the In Germany, a group of researchers recently discovered one of the rarest types of black holes in the universe. The researchers were observing a star cluster in the vicinity of a supermassive black hole called Sagittarius A (Sgr A) at the center of the Milky Way. They then discovered signals of an intermediate-mass black hole, a type of black hole sometimes referred to as the “missing link” of black holes, according to .
Black holes range in size from supermassive to primordial, with intermediate black holes found above primordial. They are thought to have formed just after the Big Bang and act as “seeds” for the creation of supermassive black holes.
The star cluster believed to be the last intermediate-mass black hole, called IRS 13, was moving in an orderly pattern when they expected them to be arranged randomly. The researchers concluded that the star cluster had to be interacting with the supermassive black hole and “there must be something inside the cluster to allow it to maintain its observed compact shape,” according to a statement from the University of Cologne.
Plans are underway to make further observations of the intermediate black hole. They will use the James Webb Space Telescope and the Extremely Large Telescope in Chile which is currently under construction (and yes, that's ).
In 2020, scientists using the Hubble Space Telescope discovered the ripples created by their formation. Until then, intermediate-mass black holes were considered a “missing link” between stellar-mass and supermassive black holes and could provide more insight into the formation of black holes and the universe.